泡桐木材防变色处理配方优选试验研究

为防止泡桐材的变色降等，采用防变色剂、耐光剂、渗透剂组成的防桐木变色剂配方处理桐木板材，观察其对色度ａ＊、ｂ＊、色差ＤＥ＊、明度Ｌ＊的影响。通过正交试验选择最佳工艺参数。处理后的泡桐板材可达到出口一级品之指标，颜色纯洁，保持木材天然本色。     

Analysis of nutrient depletion in a radiata pine plantation

A trial in an 11-year-old stand of radiata pine (Pinus radiata D. Don) was used to analyse the effects of accelerated loss of nutrients from the site on forest productivity and nutrient status. Raking of litter was undertaken over 14 years prior to thinning, then for 2 years after thinning at which time the trial was destroyed in a wind storm. The experimental design was a factorial of three main treatments: (i) removal (raking) versus nil removal of the forest floor, (ii) replacement or non replacement of nutrients to adjust for imbalances between nutrients in litter and those in the tree stem, and (iii) complete replacement (or not) of all nutrients removed in the litter. Additionally, a small trial was incorporated to address components of physical aspects of litter removal by comparing raking with ‘raking and a cover of woven plastic mesh’. Raking and nutrient additions were carried out approximately every 6 months.Over the study period, the raking treatment removed about 75 Mg ha⁻¹ of organic material with contained nutrients (559 kg ha⁻¹ of N, 68 kg ha⁻¹ of P, 323 kg ha⁻¹ of Ca, 91 kg ha⁻¹ of Mg, 243 kg ha⁻¹ of K, 0.9 kg ha⁻¹ of B) and this related to about four normal sawlog harvests or one total tree harvest. Up to the time of thinning, raking reduced basal area increment by 25% while raking together with replacement of nutrients reduced this by about 12%. Nutrient additions to unraked plots led to increases of up to 14% in basal area increment. The raking treatment reduced foliage nitrogen and this was correlated with reduced growth while other nutrients such as boron and sulphur were reduced but not to a degree to affect growth or health. The results were used to assess the effects on soil nutrient status and growth of different harvesting regimes (wood only, wood plus bark, total tree).     

泡桐树冠结构与抗风性研究

调查了６个泡桐无性系的１２个树冠结构因子，并对９个因子进行了主因子分析，结果表明，将９个因子结合为２个主因子，可以包含９０．５％的树冠信息，并认为通过树冠结构来选择抗风无性素是可行的，理想的抗风无性系应是一级侧枝多而较细，新梢夹角较小，树冠较高的细枝塔形结构。     

光周期和低温处理对泡桐叶片抗性影响研究

对毛泡桐1年生实生苗进行不同光周期和低温处理。结果表明:在相同光周期条件下,随着温度的降低SOD与CAT活性逐渐降低;MDA与脯氨酸含量逐渐上升,D16L8和D14L10光周期条件下较D8L16和D12L12条件下提前进入休眠。     

泡桐人工林生态系统养分循环的研究

桐粮间作生态系统在黄淮海平原地区具有广泛的代表性。研究比较泡桐的养分循环律,对挖掘其生产潜力,保证高产高效益,维持系统的稳定和平衡具有重要意义。一、试验地概况试验地位于河南省扶沟县江村乡泡桐试验场,东经114°32′,北纬32°0′,属暖温带季风气候,年均日照2361h,年均太阳辐射59.48kcal/cm~2,年均温度14.4℃,年均降水量678.5mm。≥0℃积温5272.8℃,≥10℃积温4692.6℃,年无霜期215d。该区属黄河冲积平原,土壤为沙壤土,pH为7.5,土层深厚,地势平坦,土壤肥沃,距地面1m左右有一粘土间层,厚30cm,保肥保水,对深根性的泡桐生长十分有利。     

桐竹混交培育泡桐单板材的研究

利用生物种群共生的竞争作用，通过３种密度的桐竹混交试验，研究在复层混交条件下培育泡桐单板材的可能性。结果表明，桐竹混交在沿海地区有较强的抗风倒能力，能显著地提高泡桐的枝下高和主干高，使树干形数和圆满度显著增大，泡桐的单板材出材量提高５０％以上。     

徐州人工侧柏林适宜经营密度的研究

根据测定的不同密度侧柏林的每木胸径，绘制不同密度侧柏林的径阶分布曲线。结果表明，密度为10335株／hm^2的侧柏林需要尽快进行间伐，以减少林木之间的竞争。根据侧柏人工林胸径和冠幅的相关关系，编制了适宜的经营密度表，为徐州人工侧柏林的经营管理提供了理论依据。     

Productivity and nutrient uptake of newly released wheat varieties at different sowing times under poplar plantation in north-western India

Standardisation of cultural practises is one of the primary objectives to make the system ecologically sustainable and economically viable. In this context, the present study was conducted to optimise the time of sowing in relation to newly released wheat varieties under 4–6 year old poplar block plantation. Six widely grown wheat varieties (PBW 502, PBW 343, WH 542, PDW 274, PBW 509 and PBW 373) were intercultivated during three consecutive crop growth seasons at three times of sowing (mid November, late November and mid December) under block plantation of poplar (Populus deltoides Bartr.) clone G-48. The grain yield and nutrient uptake of wheat varieties was higher in open conditions than under the trees. The wheat variety PBW 502 out yielded the rest of wheat varieties over different sowing times. The highest grain yield was recorded when crop was sown during mid November over the 3 years. Thus adoption of PBW 502 under poplar plantation would substantially improve the overall productivity of the system without any additional input cost. All the varieties performed better when sown early compared to one-month delay. The various growth parameters like tiller height and number, spike length and 100 grain weight contributed significantly towards higher grain yield in early sown conditions (mid November) under poplar irrespective of its age of plantation. The nutrient uptake (N, P and K) by wheat straw and grain was higher in early sown crop with longer growth span than the late sown crop. The higher quantity of N, P and K was removed from soil by PBW 509, PBW 373 and PBW 343, respectively.     

湿地松人工林矿质营养循环的研究

利用一块天然集水区 ,研究了湿地松人工林内K、P、Ca、Mg、Zn、Cu、Fe、Mn等矿物质元素。 1998～ 1999年通过降雨输入、地表径流输出以及积累、归还和吸收等循环过程。湿地松人工林有较高的生产力 (生物生产量为 2 0 349t·hm-2 ·a-1、材积生长量为 9 40 8m3·hm-2 ·a-1) ,原因在于它对矿物质元素有较高的利用率。林分矿质元素支出大于收入 ,并且归还量少 ,林分矿质元素循环效率低。建议采用阔叶树混交等方法调控湿地松林 ,以提高林分生产力 ,建立良性循环的生态系统     

STUDY ON THE SITE OF KOREAN PINE PLANTATION ON THE MAOER MOUNTAIN

1NTRODUCT1oNMaoerMountainliesintheeasternpartofnortheastChinamountainareawithinthenaturalgeographicaldistributionrangeofavaluabletimberspeciesofKoreanpine(PinusKoraiensis).Foraboatmorethanlooyears,cuttinganddestroyingcontinued;f9wnaturalprimaryKoreanpineforestsleft.AlargeareaofKoreanpineplantations,nevertheless,has'grownupastimegoing.Itisapressingproblemforushowtocultivatethemwell,andtorecoveranddevelopthemraPidlyinourforestproductionandscientificresearch.FortheKoreanpinetree,peopledid…     

Litterfall, litter decomposition and nutrient dynamics in a subtropical natural oak forest and managed plantation in northeastern India

In northeastern India, subtropical forests are over-exploited for timber, fuel wood and common agricultural practice like shifting cultivation, which are responsible for the degradation of natural forest. In degraded areas, large-scale plantations of different species of Quercus have been raised since 1980 for the production of economic Tasar silk. Conversion of natural forest into plantation affects the process of nutrient cycling due to management practices. Thus, it would be of importance to study the litterfall, litter decomposition process and the factors regulating the rate of litter decay in these ecosystems to improve recommendations for their management and conservation. We recorded litterfall by using litter traps and decomposition of leaf litter by nylon net bag technique to understand the amount of organic matter and nutrient return and their release in soils of forest and plantation in Manipur, northeast India. Total litterfall was 419.9 g m⁻² year⁻¹ in plantation and 547.7 g m⁻² year⁻¹ in forest. Litter decomposition rate was faster at plantation site than the forest in the early stage of litter decomposition whereas the reverse was observed at later stages of decomposition. Stepwise regression analysis showed the significant role of relative humidity and mean temperature on mass loss rates in the forest. Relative humidity, maximum temperature, population of fungi and actinomycetes were the best predictor variables for mass loss rates in plantation. Nutrient retranslocation efficiency and the immobilization of N and P in forest litter were higher than plantation. This suggests that Q. serrata growing in natural ecosystem in oligotrophic condition adapted strong nutrient conservation mechanisms to compete with the other plant species for the meager soil nutrients. The same species in plantation loses these adaptive capabilities because of exogenous supply of nutrients and in the absence of intense competition with other plant species. Thus, the optimization of organic and chemical fertilizer input in plantation is recommended for maintaining the soil fertility level to produce quality leaf for silkworm by conserving essential nutrients in the system.     

红壤坡地泡桐林地表径流和养分流失研究

在红壤坡地泡桐林地设置3个不同处理研究施肥对地表径流和养分流失的影响.试验结果表明:林下植被覆盖能有效的降低红壤坡地产流、产沙量以及氮、磷流失量;氮的流失主要以径流水溶性氮为主.磷的流失则是以泥沙携带为主;林地施肥增加了径流水溶性总氮、总磷浓度,而对泥沙结合态氮、磷浓度影响不大;氮素的流失浓度和流失量都比磷素高;在降雨...     

Some of the properties of particleboard made from paulownia

The objective of this study was to determine some of the properties of experimental particleboard panels made from low-quality paulownia (Paulownia tomentosa). Chemical properties including holocellulose, cellulose, lignin contents, water solubility, and pH level of the wood were also analyzed. Three-layer experimental panels were manufactured with two density levels using urea–formaldehyde as a binder. Modulus of elasticity (MOE), modulus of rupture (MOR), internal bond strength (IB), screw-holding strength, thickness swelling, and surface roughness of the specimens were evaluated. Panels with densities of 0.65 g/cm³ and manufactured using a 7-min press time resulted in higher mechanical properties than those of made with densities of 0.55 g/cm³ and press times of 5 min. Based on the initial findings of this study, it appears that higher values of solubility and lignin content of the raw material contributed to better physical and mechanical properties of the experimental panels. All types of strength characteristics of the samples manufactured from underutilized low-quality paulownia wood met the minimum strength requirements of the European Standards for general uses.     

人工林的土壤结构质量研究--以长江上游桤柏人工混交林为例

长江上游生态建设中,典型区营林10–20年的人工混交林有纯林化、衰败退化的演化趋势。本文以长江上游地区川中丘陵的人工林典型土壤为例,并以长江上游未受人为不良干扰的贡嘎山天然林土壤为对照,研究了人工林退化的土壤结构质量问题及其防治措施。结果表明:人工林土壤结构质量远不如天然林土壤。指出长江上游人工林土壤结构质量的退化,是人工林退化的重要影响因素。人工林土壤结构退化的主要原因是人为干扰,缺乏保护和科学管理。主要防治对策是:封禁生态修复和采取恢复枯枝落叶层、施有机肥等措施。     

红皮云杉人工林和天然林管胞性状的变异研究(英文)

本文分别对凉水地区的红皮云杉天然林和帽耳山地区的红皮云杉人工林的管胞性状进行了研究,方差分析结果表明：管胞长度、管胞直径和管胞壁厚度在各年轮间都存在显著差异。管胞的性状从隋心到树皮都呈现出增加的趋势;天然林中,管胞各性状间存在显著的正相关;人工林中,管胞长度和管胞直径呈明显的正相关,但管胞长度和管胞直径分别与管胞壁厚度存在显著的负相关关系。天然林和人工林相比,管胞长度和管胞直径都没有太大差异,只是在15年生以前,人工林的管胞壁厚度稍大于天然林。     

Effects of competition on growth of Amur linden plantation

IntroductionCompetitionorinterf6renceisimportantinfOrestgrowthandstandstructure(Weiner1982,1984).ForexampIe,thesizeofindividuaIcrownsanddiametersisaffectedbycompetition.Mbstint6rferencestudieshavefocusedonthemeanperformance0fplantsinreIationtodensity(Harper1977)andneighbouringdistance(Martinetal.1977;Weiner1984,Bigingeta[1992).Theyuseddistance-dependentcompetitionindices(Cl)todescribeinfluencefOrindividuaItreesthatincIudesaIIcompetitorsinthezoneofinfIuenceandprovidebettercorrelationswit…     

不同种泡桐叶片愈伤组织诱导及其植株再生(英文)

在确定5种泡桐叶片诱导愈伤组织基本培养基为MS的基础上,通过不同的NAA和BA的组合,筛选出了毛泡桐(Paulownia tomentosa)、南方泡桐(Pauiownia australis)、白花泡桐(Paulownia fortunei)、兰考泡桐(Paulownia elongata)和豫杂一号泡桐(P.tomentosa x P. fortunei)叶片愈伤组织诱导、芽分化和根分化的最适培养基。MS+0.5NAA+4BA、MS+0.3NAA+2BA、MS+0.5NAA+4BA、MS+0.3NAA+6BA和MS+0.3NAA+8BA分别为五种泡桐树种叶片愈伤组织诱导的最适培养基,上述树种的叶片愈伤组织诱导芽分化最适培养基分别为MS+0.3NAA+12 BA、MS+0.3NAA+12 BA、MS+0.5NAA+12 BA、MS+0.5NAA+12 BA和MS+0.7NAA+12 BA,最后找出了5种泡桐芽诱导根的最适培养基分别为1/2MS+0.1NAA、1/2MS+0.1NAA、1/2MS、1/2MS+0.3NAA和1/2MS+0.5NAA。这些结果为开展泡桐基因工程研究和利用不同种泡桐叶片原生质体融合培育泡桐新品种提供了参考。     

红松人工林小气候效应的初步研究

通过对红松人工林内小气候因子与对照区气候因子的对照分析，表明林分具有缓热、缓冷和涵养水源的作用；小气候的变化是一个漫长的过程，且其变化幅度在很小的范围内。     

华北石质山区侧柏人工林根系呼吸特征的研究

通过用环割法＋基于红外动态分析法的Li-8100,于2010年6月至2010年12月对位于河南省济源市的华北石质山区35 a生侧柏人工林的根系呼吸速率（Rr）进行研究。结果表明：（1）生长季根系呼吸的日变化明显,呈单峰曲线,进入非生长季后,根系呼吸无明显的日变化。（2）侧柏林根系呼吸季节变化明显,最大值出现在夏季的8月,最小值出现在冬季的12月。进入生长季后根系呼吸贡献率呈上升趋势,至10月左右达到最大值52.11%,然后开始下降。（3）侧柏林Rr与5 cm深度处的土壤温度呈极显著的指数相关关系（p〈0.01）,表征根系呼吸对土壤温度敏感性大小的参数Q10值为2.46;Rr与土壤含水量呈显著的二次曲线关系（p〈0.05）;侧柏根系呼吸速率受土壤温度和湿度的共同控制,二者可以共同解释侧柏林根系呼吸速率变化的84.4%,其中土壤温度是影响根系活动的最主要环境因子。     

A STUDY ON GROWTH OF PLANTATION ON SODA-SALINE-ALKALI SOIL

If some suitable treatments are used plantations can be grown and established on thesoil of soda-saline-alkali with the soil condition of PH 8.5—9.6,salinity 0.1—0.3％ and normalityratio of saline base Na~+/(Ca~(++)+Mg~(++))≥4.From the results of plot Inventery and tree stem ana-lysis,the increment of Poplus simonigra is highest. For 9 years,the volume can reach 100 m~3/ha,the biomass(above ground)can reach 28.7 ton/ha.Poplus simonigra grows very well on the allkinds of soda-saline-alkali soils except for the alkali spot with the worst Soil condition.So Poplussimonigra is a good tree species for planting on the Soil of soda-saline-alkali.